Plug for molten metal containers

ABSTRACT

A plug for outlet flow control of molten metals and/or slag from scoops or ladles wherein pouring is effected through the bottom thereof. The plug body is formed of a refractory material and has a first centrally disposed cylindrical cavity in its end face which cavity terminates in a flat bottom. At the center of the flat bottom of the cavity there is provided a second cavity provided with a thread for receiving the threaded stub of the scoop or ladle rod so that the latter may be attached to the plug. The threaded portion of the plug body is used only to sustain the weight of the plug body itself and to transmit the opening forces. When the scoop or ladle rod is covered by a column of refractory sleeves, the weight of the column is supported by a flange at the bottom of the rod and a nipple of refractory material disposed within the first cavity surrounding the rod and resting on the upper surface of the flange. All spaces between the assembled parts are filled with a refractory mortar.

[72] Inventor Jose Joaquim Cardoso Belo Horizonte, Brazil [21 Appl. No. 770,982 [22] Filed Oct. 28, 1968 [45] Patented [73] Assignee Jan. 19, 1971 Magnesita S. A. Montes Claros, Minas Gerais, Brazil a corporation of Brazil [3 2] Priority Jan. 5, 1968 [3 3] Brazil [3 1 196,053

[54] PLUG FOR MOLTEN METAL CONTAINERS 1,662,600 3/1928 Cox et al 222/566 2,005,311 6/1935 Belding 222/559 3,195,198 7/1965 Hoopes IlI.... (222/559) 3,200,457 8/1965 Wagstaff 222/1 Primary Examiner-Samuel F. Coleman Attorneys-EmoryL. Groff and Emory L. Groff, Jr.

ABSTRACT: A plug for outlet flow control of molten metals and/or slag from scoops or ladies wherein pouring is effected through the bottom thereof. The plug body is formed of a refractory material and has a first centrally disposed cylindrical cavity in its end face which cavity terminates in a flat bottom. At the center of the flat bottom of the cavity there is provided a second cavity provided with a thread for receiving the threaded stub of the scoop or ladle rod so that the latter may be attached to the plug. The threaded portion of the plug body is used only to sustain the weight of the plug body itself and to transmit the opening forces. When the scoop or ladle rod is covered by a column of refractory sleeves, the weight of the column is supported by a flange at the bottom of the rod and a nipple of refractory material disposed within the first cavity surrounding the rod and resting on the upper surface of the flange. All spaces between the assembled parts are filled with a refractory mortar.

' PATENIEUJANIQIBYI 35563 59 j sum 2 or 4 INVENTOR (JOSE JOAQUIM CARDOSO ATTORNEY v PATENTEU JAN] 9 ISYI v sum 3 or 4 INVENTOR JOSE JOAQUIM CARDOSO ATTORNEY PATENTEDJANIQIBYI I mm INVENTOR JOSE JOAQUIM CARDOSO I ATTORNEY I v PLUG FOR MOLTEN METAL CONTAINERS This invention relates to a plug for metal scoops or ladles in metal mills and foundries to control the outlet flow of metals and/or slag.

In metal mills and foundries the transport and short term storage of molten metals is effected in equipment known as a scoop or ladle.

Such equipment, which will hereinafterbe referred to as scoops, can discharge-their contents indifferent manners, namely bytilting and pouring from a mouth, or by means of a siphon channel, or from the bottom of the scoop by means of a plug valve arrangement. It is the latter arrangement to which this invention relates. a

The plug used in the plu valves generally comprise a plug body mounted .on one end of a steel scoop rod, which rod is covered by a column of refractory sleeves. In all arrangements, the plug has generally similar aspects and external dimensions. but there are a multiplicity of internal arrangements depending on the method of joiningthe plug body to the end of the rod.

The more generalized of theknown plugsarc those accord ing to the DIN standards and those known by the name Rotolock.

The Rotolock plugs have a central threaded opening which accommodates a flange at the end of the scoop rod. An externally threaded ring of refractory material, known as a nipple is screwed into. the threaded hole to hold the flange and the plug body together.

According to the present invention thereis provided a plug for outlet flow control of molten metals and/or slag from scoops or other containers, comprising a plug body of refractory material, having a first cylindrical cavity centrally disposed in the end face thereof, said first cavity having a flat bottom and having at the center of said bottom a secondcavity provided with athread.

Thus it will be seen that the plug according to the present invention is easier to manufacture than the hitherto known plugs and is therefore more economical, but in relation .to its assembly on the rod it has the same facility as the known plugs.

The invention willnow be described in greater detail by way of example with reference to the accompanying drawings, in which:

F IG. 1 is a longitudinal sectional its rod;

FIG. 2 is a view similar to FIG. I showing a plug of a different design;

FIG. 3 is a plan view of the plug shown in FIG. 2;

FIG. 4 is a perspective view. partly in section, of the plug shown in FIG. 2;

FIG. 5 is an exploded perspective view different design; 1

FIG. 6 is an exploded perspective view of a plug of a further different design;

FIGS. 7 and 8 show detail views of the lower end of a scoop rod;

FIGS. 9 and 10 show a plan view andan elevation respectively of a modified construction of the lower end of the scoop rod;

FIGS. l1, l2 and 13 each showsa view similar to that of FIG. 1 of a plug of different design; and

FIG. 14 shows a view similarto that of FIG. 1 of a plug of yet another different design, and also shows part of the refractory sleeve placed over the scoop rod.

Throughout the drawings, like reference numerals are used view of a plug mounted on of a plug of another to indicate like parts and it will be seen that-the plug comprises 1 or as a cylinder with a hemisphere, possibly slightly flattened at one end, or as a cylinder having at one of its' ends a frustum of a cone with rounded corners as shown in F I6; 14.

In all cases the plug body 6 has at the center of its flat side a cylindrical cavity 9 of determined diameter and depth with a flat bottom face. lnthe center of the flat bottom face is a further cavity 10 (FIGS. 6, 11,12 and 13) provided with screw threads, which may be cylindrical, round. triangular. quadrangular, square, trapezoidal. or any other suitable form.

A steel scoop rod 1 to which the plug body 6 is to be attached terminates at one end in a flange 4 and a stub 5 provided with an external thread corresponding to that in the cavity 10. The threaded stub 5 may. for economic reasons, be replaceable and is then manufactured separately from the rod 1 and is connected thereto by any suitable machine screw thread as indicated in FIGS. 7 and 8. where the stub 5 is provided with a threaded extension 13 which screws into mating threads in a bore 12 in the end of the rod 1.

Also forming part of the plug is a nipple 2 which is formed as a ring of refractory'material, which may be the same as that used for the plug body 6, or any other suitable material.

The plug is assembled by screwing the plug body 6 onto the stub 5 until the flange 4 seats firmly on the flat bottom face of the cylindrical cavity 9. and then'sliding the nipple 2 over the rod I into the cavity 9.

The assembly is completed by means of refractory mortar, for example, air-curing or graphitic, which fills all the spaces and interstices remaining'betwecn the parts. I

In order to ensure a correct seating of the flange 4, it is preferred, as shown in FIGS. 9 and 10, to provide the stub 5 and the lower face of the flange 4 with grooves 11, 11', respectively, As a result, before assembly anexcess of mortar can be placed in the cavity 10 and as the stub 5 is screwed in this excess can escape from the cavity and from below the flange 4 by way of the grooves 11, 11' to rise above the flange 4 to fill the space between the plug body 6 and the nipple 2. thus ensuring that all the internal intervals are filled.

The nipple 2 may be formed as a cylindrical tube as shown in FIGS 1, 6, 11, 12, 13 and 14, or as a'cylindrical tube with one end externally chamfered as shown in F IGS .2, 4 and 5.

The plug body 6 may have its upper surface s'mooth(FIGS. Zand 4) or with a recess 3 (FIGS. 1, l2 and 13) or with a raised collar 8 (FIGS. 5, 6, 11 and 14).

In the case of FIGS. 2 and 4, the nipple 2 is so dimensioned that when properly seated in the cavity 9 its upper end will project slightly above the surrounding surface of the plug body 6. In this way, it is ensured that whcn'thc rod 1' is covered by its column of refractory sleeves 17 (see FIG. 14)-the weight of the column is supported by the nipple 2, and thus by the flange 4, and not by the body 6. Thus the construction embodying the present invention ensures that the threaded portion of the plug body 6 carries only the weight of the body itself since the column of refractory sleeves is supported by the nipples 2 and flange 4, and the force required for closing the valve is exerted on the body 6 by way of the flange 4 and the flat bottom of the cavity 9.

As will be seen from the foregoing, the plug to which the present invention relates possesses the advantageous characteristics of the Rotolock plugs andthe threaded plugs according to the DIN standards without having any of the disadvantages of such plugs, namely:

Whilein the DIN plug the thread is used to maintain the plug body and the refractory column, it also serves as an intermediary for the exertion of the efforts for closing and opening the plug valve, which impose a general limitation on utilizatron.

In the Rotolock plug, the construction of the threaded nipple is a delicate operation which makes the nipple an expensive part, the cost price of which often reaches that of the plug body itself.

In the plug embodying the prescntinvention, the threaded portion is used onlyto sustain the weight of the plug body itself and to transmit the opening forces, which in any event are assisted-by the different densities of the refractory plug body and the molten metal.

The closing forces are transmitted by vertical pressure on the plug body in the direction of its longitudinal axis by the lower face of the flange 4 on the flat bottom of the cavity 9. The weight of the refractory column of protective sleeves is carried by the flange 4 through the intermediary of the nipple 2. and the nipple itselfis simple to construct since it is smoothsided.

lt will also be seen that in the zone of greatest erosion by the flow of metal from the scoop, the plug embodying the present invention has a greater thickness of refractory material than is the case with known plugs. although the external dimensions can remain almost identical.

The plug may be used in any scoop or container of any size in which pouring is effected through the bottom. including containers of liquid metals for regulation of flow in auxiliary equipment for the continuous or intermittent production of ingots.

lclaim: I

l. A plug for outlet flow control of molten metals and/or slag from scoops or other containers, comprising a plug body of refractory material. having a first cylindrical cavity centrally disposed in the end face thereof. said first cavity having a flat bottom and having a the center of said bottom a second cavity provided with a thread. a metal rod having at one end a flange and a threaded stub. said plug body being screwed onto said stub so that said flange lies closely against the bottom of the first cavity. a nipple in the form of a ring surrounding said rod and accommodated in said first cavity. said nipple being so dimensioned that when positioned in the first cavity the upper edge thereof protrudes above the surrounding surface of the plug body. a column of refractory sleeves covering said rod. said column being supported on the protruding upper edge of said nipple. the interstices and spaces between said parts being filled with refractory mortar. said threaded stub and the lower surface of said flange of the rod being provided with grooves to permit the escape ofexcess mortar from below said flange.

2. A plug as claimed in claim I. wherein the threaded stub is separable from the rod and is connected thereto by means of a screw connection.

3. A plug as claimed in claim 1. wherein the plug body has a recess surrounding the first cavity.

4. A plug body as claimed in claim 1. wherein the plug body has a raised collar surrounding the first cavity. 

1. A plug for outlet flow control of molten metals and/or slag from scoops or other containers, comprising a plug body of refractory material, having a first cylindrical cavity centrally disposed in the end face thereof, said first cavity having a flat bottom and having a the center of said bottom a second cavity provided with a thread, a metal rod having at one end a flange and a threaded stub, said plug body being screwed onto said stub so that said flange lies closely against the bottom of the first cavity, a nipple in the form of a ring surrounding said rod and accommodated in said first cavity, said nipple being so dimensioned that when positioned in the first cavity the upper edge thereof protrudes above the surrounding surface of the plug body, a column of refractory sleeves covering said rod, said column being supported on the protruding upper edge of said nipple, the interstices and spaces between said parts being filled with refractory mortar, said threaded stub and the lower surface of said flange of the rod being provided with grooves to permit the escape of excess mortar from below said flange.
 2. A plug as claimed in claim 1, wherein the threaded stub is separable from the rod and is connected thereto by means of a screw connection.
 3. A plug as claimed in claim 1, wherein the plug body has a recess surrounding the first cavity.
 4. A plug body as claimed in claim 1, wherein the plug body has a raised collar surrounding the first cavity. 